One common technique for harvesting forage crops is to chop them with a mobile forage harvester in their field of origin at moistures between 40% and 70% harvested either by directly cutting the crop at that moisture, or by harvesting it from a pre-cut windrow that has dried to the target moisture range. The chopped forage is delivered into a transport vehicle normally capable of carrying between three and twenty tons of forage and transferred to the site of storage which is normally a pit or bunker structure. The forage is then dumped in a pile at the intake to the pit or bunker and then spread and packed with an implement that is normally a tractor equipped with a front blade for the purpose of distributing the forage in 2 inch to 10 inch thick layers so that it can be adequately packed for the exclusion of air. This packing and spreading method encourages fermentation of the forage for storage stability until it is later fed to livestock. The normal pit or bunker type of storage structure will hold between ten and five-hundred individual loads of forage.
The feeding properties, including digestibility and nutrient levels of the chopped forage varies from field to field and from area to area within an individual field. Many of the determining factors for the feeding properties of the forage can be measured at the time the crop is harvested including: the genetics of the crop; the soil type and fertility at the position the crop is removed from; the climatic conditions at the time of harvest and during the growing stages of the crop; the stage of maturity measured either by the duration since planting or the interval since the last harvest; and, the moisture content of the crop at the time of harvest. All of these factors can be associated with the areas of the field from where the forage is harvested and used as factors in calculating the feeding properties of the crop being harvested. Since a pit or bunker is filled from different fields and different areas within fields, the feeding properties of the forage placed in different areas and layers in the storage structure can vary significantly.
The production of milk from cows or the daily gain of beef cattle being fed is dependent on the nutritional quality of the feed ration of which forage is usually the dominant component. If values of the feeding properties of forage are known, they can be balanced with other components of the ration fed. The typical method for monitoring the feeding properties of the forage is to pull samples from the stored forage, send them to a lab and then adjust the levels of the other components to maximize the value of the forage in a cost-effective way. The effectiveness of this system is limited by: the number and frequency at which the samples are taken; the location from which the samples are taken and how that is matched up the actual forage as it is removed from the storage structure; and, the lag time associated with pulling the samples, sending them to a lab and waiting for the results.
In a prior invention, entitled “A system and method for identifying bales of hay”, the forage crop harvested in bales is tracked from the field by attaching an identification device to the bale as disclosed in the prior invention. This method of identification is not possible when the forage is chopped, transported and spread as loose material.
Mapping using the Global Positioning System (GPS) is common place on a two dimensional basis (latitude and longitude) and is adequate for accurately determining the field position the crop is taken from. Three dimensional mapping using GPS technology, adding vertical position information to the map is also possible and used in applications such as mining and aviation where the additional position information is needed. In the system and method that has been invented, an improvement in identifying feed quality of the stored chopped forage by associating the field position of the crop's origin and the factors associated to location that impact quality, tracking that field position to the storage structure and then generating a 3 dimensional map of the storage structure that identifies the feed by its original field location as it is removed from the structure for feeding.